Properties of Matter & Separation Methods – Lecture Review

29 question-and-answer flashcards summarizing the lecture’s core concepts on matter, its properties, and common laboratory separation methods.

What is the scientific definition of matter?

Anything that occupies space and has mass.

How are physical properties of matter determined?

By measurement or observation without changing the substance’s composition or identity.

How are chemical properties of matter determined?

By changing the substance’s identity and observing how it interacts with other substances.

Give three common examples of physical properties.

Color, odor, and density (others include taste, melting point, hardness, conductivity).

What is an example of a chemical property that involves oxygen?

Oxidation (e.g., rusting or combustion).

Define extensive properties and list two examples.

Properties that depend on the amount of matter; examples: mass and volume.

Define intensive properties and list one example.

Properties independent of sample size; example: density.

What is density?

Mass per unit volume of a substance.

What does the boiling point describe?

The temperature at which external pressure equals the vapor pressure of a liquid, causing it to boil.

What is the melting point of a substance?

The temperature at which solid and liquid phases coexist in equilibrium.

Why do gases typically have lower densities than solids and liquids?

Gas molecules are separated by large amounts of space, reducing mass per unit volume.

What is specific heat capacity?

The amount of energy required to raise the temperature of a given mass of a material by 1 °C.

Define ductility.

A material’s ability to deform permanently under tensile (pulling) stress without breaking.

Define malleability.

A metal’s ability to be deformed under compression (hammering or rolling) into thin sheets without cracking.

What is solubility?

The maximum amount of a substance that will dissolve in a given quantity of solvent at a specified temperature.

What do electrical properties of a material include?

Its ability to conduct electric current, resistivity, electrical conductivity, and temperature coefficient of resistance.

What is a magnetic property?

The capability of a material to respond to or be used in a magnetic application.

Define flammability.

A substance’s ability to burn or ignite, causing fire or combustion.

Define reactivity in chemistry.

The tendency of a substance to chemically combine with other substances, ranging from highly reactive to unreactive.

What is corrosivity?

The ability of a substance to deteriorate or destroy other materials upon contact, often via chemical reaction.

Which separation technique removes an insoluble solid from a liquid using a porous barrier?

Filtration.

Which technique separates a soluble solid from its solvent by heating?

Evaporation.

What is decantation?

Pouring off the upper liquid layer (supernatant) to separate it from a settled solid (precipitate).

Why is centrifugation used in the laboratory?

To speed up the settling of precipitates based on density differences (e.g., separating blood components).

Describe distillation.

A process that vaporizes components of a liquid mixture, then condenses and collects them separately based on boiling points.

What is electrolysis?

Decomposition of a compound in solution using an electric current between a positive anode and negative cathode.

How does magnetism serve as a separation method?

By attracting and removing magnetically susceptible solids from a mixture.

What principle does chromatography use to separate substances?

Differences in solubility (or affinity) between the components and the mobile phase, causing them to travel at different speeds.